Retail Facility Exemption — When Does It Apply?
2001–2018
Archived OSHA letters applied a more-than-50% test: a facility qualified if over half of its income from the covered chemical came from direct sales to end users. After a 2016 court decision struck down OSHA's 2015 redefinition, OSHA's 2018 enforcement memo exempts three farm-supply wholesale NAICS codes from citation and applies discretion elsewhere.
Laboratory Exemption — Scope and Limits
1994–2003
There is no lab exemption in the standard. A true laboratory using below-threshold quantities isn't covered, but OSHA says a lab, research, or pilot operation with a threshold quantity is subject to PSM. Whether product is sold is irrelevant.
Connected Vessels — Single Process TQ Calculation
1994–2017
Interconnected vessels, and separate vessels close enough to be involved in a potential release, are one process, even if valve-isolable or only occasionally connected. The threshold is based on the amount in the process at any one time, with flammable liquids, flammable gases, and each Appendix A chemical aggregated separately.
Flammable Liquids — The 10,000 lb Catch-All Coverage Rule
1993–2024
A Category 1 flammable gas or a flammable liquid with a flashpoint below 100°F (37.8°C) triggers PSM at 10,000 lb in one process, even if not on Appendix A. OSHA aggregates co-located containers (aerosol cans, pre-charged equipment in warehouses), and the atmospheric storage exception does not apply once a tank feeds a process.
Normally Unoccupied Remote Facilities
1998–2017
A NURF must meet all three tests: periodic visits only, no permanently stationed employees, and geographically remote from other buildings, processes, and people. OSHA approved a chlorine site visited about 1.5 man-hours a day, and says NFPA spacing alone does not make a site remote.
Replacement in Kind — The Definitive Definition
1996–2006
Replacement in kind is defined as a replacement that satisfies the design specification. True RIK needs no MOC and no MOC paperwork, but OSHA says equipment PSI must still cover replacement parts. Changes beyond RIK, including maintenance procedure and inspection frequency changes, go through MOC.
Temporary Changes — Same MOC Rules, Plus a Time Period
1994–2006
Temporary changes follow the same MOC requirements as permanent ones, including the necessary time period in (l)(2)(iv). OSHA's PSM compliance directive tells inspectors to check for time-limit authorizations and steps to return the process to status quo after temporary changes.
Instrumentation Changes and Set Point Adjustments
1995–2005
OSHA treats ISA 84 as RAGAGEP for safety instrumented systems. SIS and critical instruments are MI equipment, and changes other than replacement in kind, including test frequency changes, require MOC.
Organizational Changes and Staffing Reductions
1996–2009
Organizational, staffing, and budget changes trigger MOC when they change process chemicals, technology, equipment, procedures, or facilities, such as reduced operator staffing or stretched maintenance intervals. Corporate or administrative changes unrelated to operations don't.
PHA Team Composition Requirements
1996–2013
A PHA must be done by a team with engineering and operations expertise, an employee experienced in that process, and someone knowledgeable in the method. One person drafting a PHA for others to sign is not a team.
PHA Revalidation — The 5-Year Clock Doesn't Pause
1993–2020
PHAs must be revalidated at least every 5 years. The clock does not pause during shutdowns; an expired PHA must be revalidated before restart. Revalidation need not be a brand-new PHA but must cover every (e)(3) item.
PHA Methodology — OSHA Does Not Mandate HAZOP
1995–2005
Employers choose from the listed methods or an appropriate equivalent methodology, and must justify an equivalent method themselves; OSHA does not approve methods. The team needs someone knowledgeable in the method.
PHA Recommendations — Timely Resolution Required
1998–2016
PHA findings must be addressed promptly, with a written schedule and documented resolution. OSHA says revalidations must confirm prior recommendations were implemented, and failing to complete documented actions can be cited.
PHA Must Address Prior Incidents
1998–2019
Every PHA must address previous incidents with catastrophic potential, and every revalidation must review all incident investigation reports and confirm their findings were incorporated. Unfinished action items can be cited.
P&IDs Must Reflect Current Installed Conditions
1998–2006
Equipment PSI, including P&IDs, must be kept current through MOC and must document the design basis, codes, assumptions, and calculations. Equipment built to older code editions needs a documented baseline showing it is still safe.
PHA Consequences — (e)(3)(iv) vs. (e)(3)(vii)
2005
OSHA distinguishes (e)(3)(iv), identifying the consequences of control failures, from (e)(3)(vii), a qualitative evaluation of the range of effects used to prioritize. A risk matrix is one acceptable method; failing to evaluate and document the range of effects is noncompliance.
Relief System Design Documentation in PSI
1998–2018
Relief system design and design basis must be documented with codes, assumptions, and calculations. OSHA has treated an ISA 84 SIS used instead of a relief device as de minimis. Relief devices are MI equipment under (j)(1)(iii).
Host and Contract Employer Training Duties
1993–2022
The host must inform contractors of process hazards and the emergency plan, control their entrance, presence, and exit, and periodically evaluate them. A host may deliver hazard training and records, but the contract employer must verify adequacy, keep the records, and still provide job-skills training.
Evaluating Contractor Safety Performance Before Award
1993–1996
Before selecting a contractor for work on or adjacent to a covered process, the host must obtain and evaluate its safety performance and programs. Coverage depends on the contractor's actual on-site activities, not its job title, and the duty exists to keep contractors from introducing hazards into covered processes.
Periodic Evaluation of Long-Term On-Site Contractors
1993–2022
The host must periodically evaluate whether contractors are meeting their (h)(3) duties: training, documentation including how understanding was verified, and following facility safety rules. OSHA says records must show employee identity, training date, and the means used to verify understanding.
MI Inspection Frequency — RAGAGEP Is the Standard
1996–2016
Inspection and test frequencies must be consistent with manufacturer recommendations and good engineering practice, and more frequent when operating experience calls for it. Records may note exceptions only if the procedure says so, and must be kept for the life of the process.
Equipment Deficiencies — Corrective Action Before Use
1996–2016
Equipment outside acceptable limits defined by PSI and RAGAGEP is deficient and must be corrected before further use, or safely and promptly with interim measures. OSHA says continued operation on interim safeguards requires MOC.
Quality Assurance — Materials and Fabrication Verification
1998–2012
New equipment must be fabricated suitable for its service and checked at installation against design specs and manufacturer instructions; spare parts must be suitable. Where records are missing, OSHA accepts analysis using the lowest assumed values.
Refresher Training — Every 3 Years at Most
1993–2023
Operators must get refresher training at least every 3 years (more often if needed), with frequency set in consultation with operators. The 3-year clock keeps running during shutdowns; challenge tests can cover knowledge but not skills; maintenance staff have no fixed refresher interval.
Initial Operator Training — Process Overview and Procedures
1993–2023
Each operator must be trained in the process overview and operating procedures before operating a newly assigned process, with understanding verified by tests, demonstrations, or similar. OSHA says maintenance staff are trained under (j)(3), not (g).
Training Records — Identity, Date, and Proof of Understanding
1993–2022
Training records must show the employee's identity, the training date, and the means used to verify understanding. OSHA expects tests, oral exams, or demonstrations; an oral challenge test must be certified by the test provider.
When PSSR Is Required — New and Modified Processes
1995–2019
A PSSR is required for new facilities and for modified facilities when the change requires updated process safety information, before highly hazardous chemicals are introduced. OSHA says slight changes go through MOC instead, and a long shutdown does not pause the five-year PHA revalidation clock.
PSSR Team — What the Standard Does and Doesn't Say
1996–2019
The standard does not specify a PSSR team or sign-off. It requires confirming construction, procedures, PHA/MOC, and training before highly hazardous chemicals are introduced, for new facilities and modified facilities whose changes require updated PSI.
Hot Work Permit — Any Flame or Spark Counts
2006–2024
Hot work includes any flame or spark-producing operation on or near a covered process. OSHA says even burning sulfur sticks to find ammonia leaks needs a permit, despite a written procedure. Permits are kept until the hot work is completed.
Compliance Audits — Complete Every 3 Years, Fix Findings Promptly
1995–2006
Compliance audits must be completed at least every three years (first one three years from startup for a new process). Deficiencies must be corrected as promptly as possible, not deferred to the next audit cycle.
